As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER INSTALLING A NEW NARCO ELT BATTERY, THE ELT COULD NOT BE RESET AFTER ACTIVATING THE ELT. REPLACEMENT DATE OF BATTERY WAS 10-1-98. BATTERIES HAVE A COMPUTER CHIP IN THEM SO ONLY NARCO BATTERIES CAN BE UTILIZED. APPARENTLY FAULT WAS IN THIS CHIP. AFTER INSTALLING ANOTHER NEW NARCO BATTERY, OPERATION WAS SATISFACTORY.